Add MerkleProofResult and validate_merkle_proof()

src/api.rs

@@ -21,10 +21,10 @@ use anyhow::Error as AnyhowError;
 use anyhow::Result as AnyhowResult;
 use sdk_common::aes_gcm::aead::{Aead, Payload};
 use sdk_common::crypto::{
-    decrypt_with_key, encrypt_with_key, generate_key, AeadCore, Aes256Gcm, AnkSharedSecretHash, KeyInit, AAD
+    decrypt_with_key, encrypt_with_key, generate_key, verify_merkle_proof, AeadCore, Aes256Gcm, AnkSharedSecretHash, KeyInit, AAD
 };
 use sdk_common::process::{check_tx_for_process_updates, lock_processes, Process, ProcessState};
-use sdk_common::serialization::{OutPointMemberMap, OutPointProcessMap, ciborium_deserialize as common_deserialize};
+use sdk_common::serialization::{OutPointMemberMap, OutPointProcessMap};
 use sdk_common::signature::{AnkHash, AnkMessageHash, AnkValidationNoHash, AnkValidationYesHash, Proof};
 use sdk_common::sp_client::bitcoin::blockdata::fee_rate;
 use sdk_common::sp_client::bitcoin::consensus::{deserialize, serialize};
@@ -1739,6 +1739,18 @@ pub fn hash_value(value: JsValue, commited_in: String, label: String) -> ApiResu
     let hash = AnkPcdHash::from_pcd_value(encoded_value.as_slice(), label.as_bytes(), &outpoint);
     Ok(hash.as_byte_array().to_lower_hex_string())
 }
+
+#[derive(Tsify, Serialize, Deserialize)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+#[allow(non_camel_case_types)]
+pub struct MerkleProofResult {
+    pub proof: String,
+    pub root: String,
+    pub attribute: String,
+    pub attribute_index: usize,
+    pub total_leaves_count: usize,
+}
+
 #[wasm_bindgen]
 /// Generate a merkle proof for a specific attribute in a process state.
 /// 
@@ -1751,16 +1763,17 @@ pub fn hash_value(value: JsValue, commited_in: String, label: String) -> ApiResu
 /// * `attribute_name` - The name of the attribute to generate a proof for
 /// 
 /// # Returns
-/// A JavaScript object containing:
+/// A MerkleProofResult object containing:
 /// * `proof` - The merkle proof as a hex string
 /// * `root` - The merkle root (state_id) as a hex string
 /// * `attribute` - The attribute name that was proven
 /// * `attribute_index` - The index of the attribute in the merkle tree
+/// * `total_leaves_count` - The total number of leaves in the merkle tree
 /// 
 /// # Errors
 /// * "Failed to deserialize process state" - If the process state cannot be deserialized from JsValue
 /// * "Attribute not found in state" - If the attribute doesn't exist in the state
-pub fn get_merkle_proof(process_state: JsValue, attribute_name: String) -> ApiResult<JsValue> {
+pub fn get_merkle_proof(process_state: JsValue, attribute_name: String) -> ApiResult<MerkleProofResult> {
     // Deserialize the process state from JsValue
     let state: ProcessState = serde_wasm_bindgen::from_value(process_state)
         .map_err(|_| ApiError::new("Failed to deserialize process state".to_owned()))?;
@@ -1771,7 +1784,7 @@ pub fn get_merkle_proof(process_state: JsValue, attribute_name: String) -> ApiRe
     // Find the index of the attribute in the commitments
     let attribute_index = state.pcd_commitment.find_index_of(&attribute_name)
         .ok_or(ApiError::new("Attribute not found in state".to_owned()))?;
-    
+
     // Generate the merkle proof for the attribute
     let proof = merkle_tree.proof(&[attribute_index]);
     
@@ -1779,16 +1792,48 @@ pub fn get_merkle_proof(process_state: JsValue, attribute_name: String) -> ApiRe
     let proof_bytes = proof.to_bytes();
     let proof_hex = proof_bytes.to_lower_hex_string();
     
-    // Create a result object with the proof and additional metadata
+    Ok(MerkleProofResult {
-    let result = Object::new();
+        proof: proof_hex,
-    Reflect::set(&result, &JsValue::from_str("proof"), &JsValue::from_str(&proof_hex))
+        root: state.state_id.to_lower_hex_string(),
-        .map_err(|_| ApiError::new("Failed to set proof field".to_owned()))?;
+        attribute: attribute_name,
-    Reflect::set(&result, &JsValue::from_str("root"), &JsValue::from_str(&state.state_id.to_lower_hex_string()))
+        attribute_index: attribute_index,
-        .map_err(|_| ApiError::new("Failed to set root field".to_owned()))?;
+        total_leaves_count: merkle_tree.leaves_len(),
-    Reflect::set(&result, &JsValue::from_str("attribute"), &JsValue::from_str(&attribute_name))
+    })
-        .map_err(|_| ApiError::new("Failed to set attribute field".to_owned()))?;
+}
-    Reflect::set(&result, &JsValue::from_str("attribute_index"), &JsValue::from_f64(attribute_index as f64))
+
-        .map_err(|_| ApiError::new("Failed to set attribute_index field".to_owned()))?;
+#[wasm_bindgen]
-    
+/// Validate a merkle proof for a specific attribute.
-    Ok(JsValue::from(result))
+/// 
+/// This function verifies that a merkle proof is valid and proves the existence
+/// of a specific attribute in a given state. It checks that the proof correctly
+/// leads to the claimed root when combined with the attribute hash.
+/// 
+/// # Arguments
+/// * `proof_result` - The MerkleProofResult containing the proof and metadata
+/// * `hash` - The hash of the attribute data as a hex string (the leaf value)
+/// 
+/// # Returns
+/// A boolean indicating whether the proof is valid
+/// 
+/// # Errors
+/// * "Invalid proof format" - If the proof cannot be parsed
+/// * "Invalid hash format" - If the hash is not a valid 32-byte hex string
+/// * "Invalid root format" - If the root is not a valid 32-byte hex string
+pub fn validate_merkle_proof(proof_result: MerkleProofResult, hash: String) -> ApiResult<bool> {
+    let root_bytes: [u8; 32] = Vec::from_hex(&proof_result.root)?
+        .try_into()
+        .map_err(|_| ApiError::new("Invalid root format".to_owned()))?;
+    
+    let proof_bytes = Vec::from_hex(&proof_result.proof)
+        .map_err(|_| ApiError::new("Invalid proof format".to_owned()))?;
+
+    let index = proof_result.attribute_index;
+    let total_leaves_count = proof_result.total_leaves_count;
+
+    let hash_bytes: [u8; 32] = Vec::from_hex(&hash)?.try_into()
+        .map_err(|_| ApiError::new("Invalid hash format".to_owned()))?;
+    
+    let res = verify_merkle_proof(&proof_bytes, &root_bytes, index, &hash_bytes, total_leaves_count)?;
+    
+    Ok(res)
 }